Insulation in North Berwick, Maine

Insulation and air sealing in North Berwick

North Berwick runs to about 38 square miles and roughly 5,129 people. It sits about 34 miles southwest of downtown Portland. That is roughly 2,238 housing units. The community dates back to 1831. We cover ZIP code 03906.

Our job history shows nothing in North Berwick so far. Plenty of sites will show you a number here anyway.

The housing stock in North Berwick

The typical home in North Berwick dates to around the early-1980s. Houses of this vintage usually got batts or blown fiber at whatever the standard of the day was, which is well short of what is recommended now. Most are one top-up away from being right.

We work across North Berwick rather than one corner of it — North Berwick Village, Doughty Falls, Five Corners, Varney Crossing, Estes Hill and Bauneg Beg included. Construction and vintage change between them, sometimes by thirty years and a whole different framing method, which decides whether a wall can be dense-packed at all.

North Berwick, set off from Berwick in 1831, grew as a mill and railroad town on the Great Works River, where a woolen blanket mill was rebuilt in brick in 1862 after a fire. Bauneg Beg Mountain, 866 feet high, is the town's highest point.

North Berwick homes in the Census numbers

The Census Bureau estimates 2,238 homes in North Berwick. 530 of them (24%) went up before 1940 — 11th of 64 places on this site for pre-1940 housing. More of today's homes date from before 1940 than from any single decade since, and 45% predate 1980. For York County as a whole the pre-1940 share is 20%, so North Berwick sits above it.

Of 2,026 occupied homes, 0% heat with utility gas and 6% with electricity; another 25% burn propane or other tank gas. Electric heat here is less common than across the county (10%), and ranks 47th of 64 on this site. Whoever comes out will ask what heats the house first: the rebate is the same on any fuel, but the saving is not.

89% of occupied homes are owner-occupied and 85% of all homes are single-family detached houses, with 65 mobile homes in the count. Read together, those numbers point toward air sealing on newer houses that already have depth.

2,238 homes, Census ACS 2020–2024 (B25034, B25040, B25003); 2,026 occupied.

Sealing comes first in North Berwick

563 of North Berwick's 2,238 homes (25%) were built in the 1980s and 1990s. The gaps in houses of that age are the parts nobody sealed: batts stuffed into the rim joist, bare spots over cathedral and tray ceilings, soffit vents buried with no baffles, can lights punched through the ceiling plane. A top-up plus a day of sealing usually covers it.

What the energy code requires in North Berwick

North Berwick enforces the Maine Uniform Building and Energy Code (2021 IECC with Maine amendments). North Berwick's Code Enforcement page names the state code as the town's building code but still lists the 2015 editions, energy code included; the town's 2026 permit application asks for the most current code requirements, which since April 7, 2025 means the 2021 editions.

For new work, the attic number under that edition is R-60, with walls at R-30, or R-20 + R-10 continuous, or R-13 + R-15 continuous, or R-20 continuous. Set that against the Department of Energy, which recommends R60 for an uninsulated attic in this climate zone and R49 for one that already has a few inches.

The 2021 IECC, Table R402.1.3, zone 6, as amended by Maine's energy rule, 08-003 C.M.R.

Do you need a permit to insulate here?

There is no published answer for North Berwick. Neither the permit-required list nor the exemption list mentions insulation or air sealing at all. That silence is not permission and it is not a prohibition. We settle it with a phone call before the crew is scheduled.

Permits and inspections in North Berwick

The published number is 207-676-3353. The department page is here.

Permitting is on us, not on you.

Rebates a North Berwick homeowner can actually use

Heating fuel in North Berwick, by the Census Bureau's count: fuel oil or kerosene in 58% of occupied homes, electricity in 6%, propane or tank gas in 25% (Census ACS 2020–2024). For North Berwick homeowners the rebate is Efficiency Maine's: $2,000 for each attic, wall or basement zone of 500 square feet or more at any income ($3,000 moderate, $4,000 low income), with $150 to $300 for attic air sealing on top. Only a Residential Registered Vendor can do rebated work, the claim goes in within six months, and a lifetime limit of $8,600 per home applies. Income-qualified households in York County can apply to York County Community Action Corp (207-324-5762) for free weatherization through MaineHousing instead. Every condition is in the rebate guide. The York County page compares the towns.

Nearby

North Berwick borders Berwick, South Berwick, Wells, Sanford and Lebanon. These are the ones we also cover, each with its own energy code and permit rule:

Elsewhere in York County we also cover:

How North Berwick compares with its neighbors

Maine sets the residential energy code statewide, so the attic figure is R-60 wherever it is published here; what changes is the permit desk, and 1 of the 7 publishes a permit rule for insulation.

All 29 York County jurisdictions side by side →

Common questions about insulation in North Berwick

Code and permit facts checked October 24, 2026, rebates October 24, 2026; housing: Census ACS 2020–2024. Sources: townofnorthberwick.org (2, 3, 4, 5, 6, 7) · maine.gov (2) · en.wikipedia.org · www2.census.gov (2) · prd-tnm.s3.amazonaws.com · efficiencymaine.com (2, 3, 4) · energystar.gov · data.census.gov. These change; confirm with the building department at 207-676-3353 or Efficiency Maine at 866-376-2463 first.